Node for setting render colour, regardless of lighting
I assume you mean a &quot;shadeless&quot; shader:

To create this you can use the Light Path node to make an emission shader which is visible only to the camera, letting other rays straight through with a transparent shader:

Casting shadows:
With a diffuse shader (or a holdout shader, black transparent shader, etc. anything that will cast a shadow and render fast) used instead of the white transparent shader:

You'll notice that there is some indirect lighting (in this case it's a slight orange tint to the shadow, because I made the diffuse shader orange)

If you don't want that orange tint, you can either:

Disable it per object by disabling Diffuse in Properties &gt; Object &gt; Ray visibility:


Disable it per material with the light path node:



Result: